Apparatus for sharpening rock-drilling-machine bits.



PATENT'ED PEB. 13, 1906.

J. A. G. KIRSTN. APPARATUS FOR SHARPENING ROCK DRILLING MACHINE BITS.

ni-. .whiff APPLICATION FILED MABJS, 1905.

muni n UNrrEn sirnrns PATENT FFIC.

JOSEPH ADOLPH GEORGE KIRSTEN, OF RANDFONTEIN, TRANSVAAL.

APPARATUS FOR SHARPENING ROCK-DRILLING-MACHINE BITS.

Specification of Letters Patent.

Patented Feb. 13, 1906.

Application filed March 15, 1905. Serial No. 250,151.

To all whom it may concern.-

Beit known that I, JOSEPH ADoLPH GEORGE KrRsTEN, a subject of the King of Great Britain, residing at Randfontein, Transvaal, have invented certain new and useful Improvements in Apparatus for Sharpening Rock- Drilling-Machine Bits and the Like, of which the following is a specification.

The improvements constituting the subject-matter of the present application have reference to apparatus or machines intended for use in the sharpening of that class of rockdrilling-macliine bit commonly known as the star7 bit. It may also be adapted to other drills or bits of similar shape whether emloyed for hand or machine drilling.

The object of the 4present invention is to construct a machine of simple design in or by aid of which the drills or bits may be sharpened with expedition and precision.

In my improved machine the drill or bit is swaged to the correct size and shape-that is to say, the webs or wings are brought up to the required gage and the corners or tips of the wings which are worn ofi' when the drill or bit is in use are worked out of the steel of which the tool is madeand the radial cutting edges simultaneously formed along the edges of the wings at the cutting extremity of the drill or bit.

I will at once proceed to describe my invention in detail by aid of the appended sheet of drawings, which illustrate a machine constructed in accordance therewith, andin which- Figure 1 represents a front elevation of the machine. Fig. 2 is a side elevation. Fig. 3 is a plan. Fig. 4 represents a front elevation of the several dies and the die holders or stops drawn to an enlarged scale. elevation of one of the dies and its holder. Fig. 6 isa side part-sectional elevation of the dolly or tool for swaging the bit. Fig. 7 is an end elevation of Fig. 6. Fig. 8 is an end elevation of the carriage which serves for supporting4 the shank or outer end of the drill during the operation of sharpening, showing also the bed and means for traversing the carriage longitudinally thereof; and Fig. 9 is an elevation of the plate to provide for access to the dies, to which is a'HiXed the rest forv the front end of the drill.

Fig. 5 is a sideA In the drawings, 1 represents a vertical plate which'is bolted or otherwise securely iiXed to one end of a table or frame 2. The table 2 comprises the side plates 3 4, which at one end are shaped to form the legs 5 and are at the other end iitted with the legs or supports 6 for carrying it at a convenient height. The plate 1 is bolted to the table 2 `through the angle-irons 7, which also strengthen the trame 2 and form supports.

In the front and at the top of the plate 1 is bolted or otherwise securely Aattached a plate 8. This plate 8 is shaped on the inside to form four boxes or radial guideways 9, which in the drawings are shown formed between parallel ribs 10, formed on the back of the plate. A hole 11 is formed through the center of the plate 8, and a coincident hole 12 is formed in a detachable plate 12, (see Fig. 9,) Xed to the back of the plate 1. 12a is provided to allow of access being obtained to the dies to iacilitatethe changing of the dies. The plate 12a is xed to the plate 1 by the cleats 12b. In the guideways 9 are arranged four stops or die-holders 13, which have attached to their inner ends the four dies 14. (See Fig. 4.) The die-holders 13 at their inner ends are formed with dovetailed recesses 15, and the dies 14 are formed with corresponding dovetailed projections 16, which iit into the dovetail recess 15 in the holders 13 and so secure the dies. The several dies 14 are shaped on the inside with V- shaped projections 17 at the center, (see Fig. 4 which iit between the wings of the drill 1LL when the latter is placed in position between the dies 14. They are formed with a rounded or curved part 18, (see Fig. 4,) which corresponds with the outer end of the wing or web of the drill in such manner that when the several dies 14 are assembled or brought together they form between them the shape of the cuttin end of the bit. As seen in Fig. 5

the curve parts 18 of the dies 14 are made parallel for a short distance, as is indicated at 19, and then incline inward, as indicated at 20, to form the taper on the wings ofthe drill in the direction of the shank. Dies are provided of similar construction to the above for operating upon the several standard sizes of drills. 1

The top vertical die D is adjustably held in The plate IOO position by means of a bridle 21, which is fixed between the plates 1 8 at the top. Through the top of this bridle 21 is screwed a bolt 22, which is attached to the top die holder or stock 13. By raising or lowering the bolt 22 the top die 14 and its stock 13 may be raised or lowered in its guideway 9 to obtain any desired adjustment. Locking-nuts 23 24 are fitted on the bolt 22 above and below the bridle 21. The other'three dies 14- that is to say, the lower verticali die 14 and the two horizontal dies 14-are adapted to reciprocate in the guideways 9 within certain limits, so that after the drill 1a has beenproj ected through the hole 12 in the back plate 1 and between the dies 14 the latter may be closed round the drill 1 while it is being swaged to the required gage. For the purpose of operating the three movable dies 14 a ever 25 is employed, which is pivotally fixed to the back plate 1 at or in proximity to the bottom thereof. The arm 26 of this lever is pivotally attached to the lower end of a vertically-arranged connecting-rod 27, which rod 27 at its upper end 'is pivotally attached to the outer end of the lower vertical die-carrier 13. This rod 27 has attached to it a plate 27 a, to which two other connecting-rods 28 29'are pivotally attached, which at their upper ends are connected with the lower arms of two levers 30.

pins or pivots 31.7 fitted between lugs 32 at the bottom corners of the plate 3 and the plate 1. The upper arms of these levers 30 are pivotally attached to the die holders or carriers 13 of the two horizontally-reciprocated dies 14. The arms of the levers 30 are formed with slots 33 to allow of the radial movement of the levers 30 about their pins 31, while permitting the die-carriers 13 to move in a rectilinear path in the guideways 9. The several connecting-rods are constructed in two parts formed with right and left hand threads and connected by the adjusting-nuts 34, formed with corresponding right and left hand threads, so that any desired adjustment of said connecting-rods may be effected to bring the several dies 14 into correct relative position to hold the drill 1a. By moving the outer arm of the lever 25 in a downward direction the several connecting-rods are raised, which forces the bottom vertical die 14 and the two horizontal dies inward round the wings of the drill la. When the lever 25 is moved in the opposite direction, the several connecting-rods are lowered, vwhich move the above-named three dies 14 away from the center and so allow the drill 1 to be removed. The lever 25, as shown in the drawings, is designed to be operated by means of a hand-wheel 35 and screw 36, working through a boss 37, formed on the outer end of the outer arm of the lever 25. The screw 36 is shown to move about a pivot-pin These levers 30 work on 38, supported in the ears 38 (see Figs. 1 and 2) at the lower end to compensate for the radial movement of the lever 25 about the pivot 39. After the drill 1"1L has been placed in position the hand-wheel 35 is operated to force the several dies 14 inward before the swaging of the drill is commenced. Instead of the arrangement shown I may employ a system of levers or other means adapted to operate .the several dies more quickly than the hand-wheel 35 and screw 36 previously described. l

j To the front plate 8 ofthe machine guides 40 may be bolted, which serve as guideways for the piston 41 or head of the percussive apparatus. This percussive apparatus may be constructed similar to an ordinary percusj, sive rock-drilling machine operated by steam,-

compressed air, or other motive liuid.

Between the guides 4() for the head of the percussive apparatus and to the front plate 8 is 'bolted or otherwise fixed a horizontal bridle 42, which serves for supporting the dolly or tool 43 for swaging the drill when it is in position between the dies 14 and for forming the cutting edges on the wings thereof. The dolly'43 is shown in detail in Figs. 6 and 7. It is'formed with a square shank 44, which worksthrough a hole in the bridle .42. The head of the dolly 43 projects for al short distance" between the dies 14. It is capable of moving inward in the parallel portions 19 of the several dies 14. A washer 45 is iitted round the shank 44 at the back of the head, and between the washer 45 and the inside of the bridle 42 is placed a ring 46, of rubber or other resilient material, which rubber ring 46 serves to keep the inner end of the dolly 43 in contact with the extremity of the drill 1a during the operation of the machine. The shank 44 of the dolly 43, which projects to the front of the bridle 42, is in line with the piston or head 41 of the percussive apparatus `and is struck by the latter at each reciprocation. The dolly 43 transmits the blow to the end of the drill 1a between the several dies 14. The face of the dolly 43 which operates on the drill 1a is made convex and is formed with four radial V-grooves 47, which form the radial cutting edges longitudinally of the webs or wings of the drill. It will be .perceived that by the convex form of the dolly 43 it operates to work out the center portions of the wings toward the tips or outer ends of the wings to bring the drill 1fL up to the gage of the dies 14 or to swage the metal from the center to iill the dies 14. The Enished drill is of hollow or concave form, so that the tips of the wings are more prominent or project farther forward than the center of the bit. Thus the metal is located where the greatest wear takes place.

For the purpose of supporting the shank or outer end of the drill while it is being oper- IOO TIO

ated upon by the dolly 43 and-between the dies 14 I provide a carriage which is adaptedv parallel angle-irons 50, which are riveted,

bolted, or otherwise fixed to the channel-iron 49 and a strengthening-plate 51 on the inside of the channel-iron 49. Between the vertical members of the angle-irons 50 are fixed a number of transverse pins 52, forming a rack longitudinally of the table 2.

The carriage is comprised of two vertical plates 53, between which plates 53 are placed two blocks 54 at either side of the table 2, to which the plates 53 are bolted or otherwise affixed. The blocks 54 rest on the top of the angle-irons 48, on which they may slide longitudinally of the table 2 in either direction. The vertical plates 53 are shaped at the bottom to project underneath the channel-irons 48, (see Fig. 8,) forming the bed for the carriage, so as to prevent the carriage being raised off its bed on the impact of the dolly with the drill. Arranged transversely of the table 2 and'journaled in the blocks 54 is a horizontal spindle 55. To retain the spindle 55 in position in the blocks 54, two collars 56 are fixed on the spindle 55 between the blocks 54. On the spindle 55 is fixed a toothed wheel or pinion 57, which engages the pins 52, forming the longitudinal rack. One end of the spindle 55 projects beyond the block 54 at one side of the machine and has attached to it a crank 58 for turning the shaft 55 and pinion 57 to move the carriage in either a forward or rearward direction. The two vertical plates 53 of the carriage are formed with semicircular or approximately semicircular recesses which receive and supporta heavy cylindrical piece or block 59, which forms the stop to receive the blow when the drill is being operated upon by the dolly 43. The cylindrical piece 59 is shown formed with two annular grooves 60, into which the plates 53 project to afford firm support for the stop. The front of the stop is formed with a recess or hole 61, into which the shank of the drill 1a is projected.

On the spindle 55 at the side of the table 2 is fixed a ratchet-wheel which is engaged by4 a pawl operated by a lever 62. The'lever 62 is long enough to afford the operator considerable power over the pawl and ratchetwheel, so that he may keep the pawl in gear with the ratchet-wheel to prevent the backward movement of the carriage when the drill is being operated upon. This ratchet mechanism 1s provided to prevent the rotation ofl the spindle 55 and pinion 57 after the carriage has been placed in position to support the drill.

The operation of this machine is as follows: The lever 62 is first raised to disengage the pawl from the ratchet-wheel on the spindle 55, and the spindle 55 is then rotated by the crank 58 to drive the pinion 57 to move the carriage in either a forward or rearward direction, according to the length of the drill to be operated upon. The shank of the drill 1a is projected into the hole 61 in the front of the block 60. The forward end or wings of the drill (which have been heated) are projected between the dies 14 until the drill abuts the face of the dolly 43. The lever 62 is then lowered to place the pawl in gear with the ratchet-wheel to prevent any movement of the carriage in a rearward direction, and the lever 62 is firmly held in that position. The lever 25 is now operated to move the lower vertical and the two horizontal dies 14 inward round the wings of the drill 1a, and the percussive apparatus 41 is then brought into operation. The percussive apparatus strikes the dolly 43, which is free to move along the parallel portion 19 of the dies 14 and so swage the drill to the gage of the dies 14 or fill up the dies by forcing the metal outward from the center to the ends of the wings. The dolly 43 at the same time forms the cutting edges along the wings of the drill. When the swaging of the drill is completed, the three movable dies 14 are moved outward from the center, the lever 62 is again raised, and the carriage moved backward to allow the drill 1a to be removed fromy the machine.

What I claim as my invention, and desire to protect by Letters Patent, is-

1. 1n apparatus for sharpening rock-drilling bits, a main vertical plate, a second vertical plate fixed thereto and having a central aperture and vertical and horizontal guideways radiating from said aperture, die-carriers in said guideways, dies attached to said carriers, a device for adjustably supporting the top vertical die, levers pivoted to the second plate and connected to the horizontal diecarriers, a lever pivoted to the mainplate and yieldingly connected with the bottom vertical die-carrier and with the levers operating thehorizontal die-carriers, and means for operating the lever pivoted to the main plate.

2. In apparatus for sharpening rock-drilling bits, in combination, an upright plate having vertical and horizontal guideways radiating from a central aperture, die-carriers in said guideways, dies attached to the inner ends of said carriers, means for supporting the top vertical die-carrier in position, and means for moving the lower vertical die- IOO IIO

IZO

carrier and the horizontal die-Carrier toward In witness whereof I have hereunto set my and away from the central aperture, a dolly hand in the presence of two subscribing wit- `ro pojeoted between he severaldies and adaptnesses. e to reci rooate etween t e same means for suppoliting said dolly in position etween JOSEPH ADOLPH GEORGE KIRSTEN' the dies, and means for supporting the drill Witnesses:

and taking the impact of the dolly on the CHAs. OVENDALE,

drill. R. OVENDALE.' 

